Flashless propellant powder composition



Patented Apr. 6, 1948 FLASHLESS PROPELLANT rowonn;

' COMPOSITION George tBa'rslcypNewflork, N. Y.-,assignor .to E. F. Drew 8aiCoi;Inc.,r aicorporation of Delaware sesame. Ap lication March "1.1942,-

Serial No. 433,717

' 7 Claims;

The present invention isdirected to propellant powders, such'as of the nitrocellulose type-andmore I particularly, L to compositions containing 5 agents intended-to assist in -the iormationof the nitrocellulose into gra-nular form and to reduce flash-of the powder:

Inconverting nitrocllixldseinto powder-grains itis customary-to add certai-ir-substances,--usua1ly organic in nature, and sometimeshavingfex plosive-propert-ies in order tOj plasticize-the nitrocellulose -and render I it more easily extruded or' molded to the desired 1 size and shape-r However;

most fthe substances heretofore-used,ior this' purpose have 'but verylimited-solvent aetion on a the --nitroeellulose-so-thatthe"p1'3iStlCiZing= efiect has beennon-uniiorm, --and--the operation-oiin corporating the plasticizer has' bee'n-ouite slow.- i

Even'whenheat isusedin the'process the-opera tion is still slow and incomplete.

To-overcomethis it has'been proposed' to use various additions, asfor example; certain eth'ers obtained-- from straight chain; pelyhydric alcohols;

but such substances present further disadvantages. that several'cheinicarreactions arenecessaryand theoperation is likely' to -result-'--in* byfproducts which are -undesirableg-and" theeffioiency of re: action thereby decreased-r 3 It is also -hig-hly=desira-ble*in propellant powdersto avoid-a flash whieh normally occurs in a gun barrel whenthegun is fired. Various, substances have been added tonthepol iderinan attempt to overcome this deficiency." However, various disadvantagesaare inherent::-in thersubstances previously used. Generally, a substance. whichrreduces the flashpi the powderis likelyto produce a considerable amount of smoke. Among such They are quite expensive -to5produce -in to exert its solvent andlubricat-ingeiiects. The' resulting from ignition of the powder andfat the same time not to adversely;eiiect-the-moisture 1 resistance of thepowden- The present" invention--also contemplates a plasticizer and a plasticized-compositionin which there is ahighdegree of solvent power for the nitrocellulose and in which there";-is a suiiicient amount of lubricationby the plasticizer' to render I the extrusion-of the nitrocellulose simple and rapid.

In practicing the present inventionI provide an agent which consists essentially of an ester oi, a lower iattyacid having iromfi to 14 carbon atoms. Preferably" aoids from8-to 12 carbon atoms are used, such as capryli caprio and lauric' acids. Acids of this type are esterified by means of aglycol etheror p0lyg1yco1.-, Usually the diand tri-ethylene and propylene'glycols aroused.

The esterification; of the acid with-theglycolmay v be conducted as 'is well;known;- since the reaction follows the well-known esterificationprocedure;

The agent maybe addedtothe-explosive material or composition in relatively small amount following is an example of the character of the compositions which have beeniound useful 5 Parts by weight Nitrocellulose 30..

Fri-ethylene glycollcaprylate 1 The amount of the agentmay bewaried to a considerable extent, depending upon the-character substances are the dialkylphthalates which; while havinglithes property of --reduci-ng the flash; give an excessive amount of a black -smoke when; used in "suilicient quantities toeliminate the fiash, Also; other substances previously -prQp sed {for theupurposaahave the disadvantage that they are more unless-water solubleandtherefore increase tha tendency ofthe -powder-toabsorb moisture from the air The present invention is, intended to provide a plasticizing agent for explosives such as of.the nitrocellulose type wherein; the plasticizer is simple in character, may be easily" produced, "and the raw materials for which are readily available.

It is also among the objects of the present invention to provide a propellant powder composition which shall be adapted to reduce the flash of the nitrocellulose, the size of th'e grain tobe produced, the nature-of modifying ingredients-if any, the speed'with which. extrusion is to take place, and various other factors.

It has been found that a mixed ester is e'm'inently suitable for the purpose, This .is formed by first providing a composi-tion ofa-the following character:

Parts by weight Caprylic acid; 3- Capric acid 1 The mixture of acids is fullyesterified withdiel or tri-ethylene glycol, in the, Welleknown mane.- ner. It is believedjthat the reactionresultsin the formation. of. mixed,.esters asnwelllas a ,mix- Such a composition .has

, Parts byweight Nitrocellulose 85 Dinitrotoluol T 10 Mixed tri-ethylene glycol capry1ate-caprate 5 Parts by weight Nitrocellulose 80 Trinitrotoluol 15 Propylene glycol caprylate 5 It is believed that the fact that the agents of the present invention have an oily nature, contributes largely to the eifectiveness thereof in the extrusion operation, since such oily products give excellent lubricating efiects. The plasticizers act rapidly as colloidizing agents and thus insure a uniformcomposition of the finished explosives. Furthermore, the agents are nonhygroscopic and therefore impart such properties to the explosive whereby the tendency to absorb moisture from the air is to a great extent eliminated. It is believed that the aliphatic nature of the plasticizer is responsible for the maintenance of the flashless character of the powder.

All these factors result in a superior finished product.

Compositions made in accordance with the present invention may be used with or without the addition of other ingredients thereto. For instance, it is common to add to smokeless powders, a stabilizer such as diphenylamine, and additions of this character may be made to the present compositions without adversely effecting the same.

The proportions the ingredients may bevaried Within wide limits, depending on the character of the explosive and other factors including the type of, gun in which the explosive is to be used, The plasticizer may range from 2 to of the mixture and the dinitrotoluol may be as much as or more. Other mixtures than the above may be treated as set forth herein, and in such cases, the amount of plasticizer will vary in accordance with the solvent power thereof for the explosive material or composition and other properties.

The above examples are intended to be illustrative of the invention and do not limit the same, the scope of the invention being set forth in the claimsappended hereto.

What is claimed is:

1. A propellant powder comprising an explosive consisting essentially of nitrocellulose having incorporated therein'a minor amount of a composition which is the substantially neutral ester of a glycol taken from the class consisting of ethylene and propylene glycols with an acid taken from the class consisting of caprylic, capric and V lauric acids.

2*..A propellant powder comprising an explosive consisting essentially of nitrocellulose, having incorporated therein a minor amount of a composition which is the substantially neutral esters of diethylene glycol with an acid taken from the class consisting of caprylic, capric and lauric acids.

3. A propellant powder comprising an explosive which is a mixture of about 8 parts of a nitrocellulose and about 1 part of a nitrotoluol, having incorporated therein a minor amount of a composition which is the substantially neutral ester of a glycol taken from the class consisting of ethylene and propylene glycols with an acid taken from the class consisting of caprylic, capric and lauric acids.

4. A propellant powder comprising a nitrocellulose explosive having incorporated therein a minor amount of a composition which is the substantially neutral mixed esters of triethylene glycol with a mixture of caprylic and capric acids.

5. A propellant powder comprising a nitrocellulose explosive and a minor amount of the mixed poly-ethylene glycol esters ofcaprylie and capric acids, the caprylic being greater in amount than the capric acid.

6. A propellant powder comprising a nitrocellulose explosive and a minor amount of the mixed poly-ethylene glycol esters of caprylic and capric acids, the ratio of.capry1ic to capric acid being about 8 to 1. v

7. A propellant powder comprising an explosive consisting essentially of nitrocellulose, having incorporated therein a minor amount of a composition which is the substantially neutral ester of triethylene glycol with an acid taken from the class consisting of caprylic, capric and lauric acids.

GEORGE BARSKY.

REFERENCES CITED The following references are of record in the file of this patent: 

